Abstract

Monodispersed Ag@SiO₂ core-shell structure nanoparticles (NPs) are synthesized at room temperature via a one-pot sol–gel synthesis method, and the synthesizing procedure is observed over reaction time in order to investigate the formation mechanism. Ostwald ripening of silver (Ag) core NPs and silica (SiO₂) shells during synthesis of core-shell NPs proceeds in parallel to reaction time. Uniform and stable Ag@SiO₂ core-shell NPs are formed at 48 h of reaction time. The hydrolysis rate of tetraethyl orthosilicate (TEOS) plays a critical role in the growth of Ag NPs and the final structure of Ag@SiO₂ core-shell NPs. The formation mechanisms of single-core and multicore Ag@SiO₂ core-shell NPs are discussed in relation to synchronous Ag core and SiO₂ shell growth. Optimal reaction conditions for critical parameters (water volume and TEOS and ascorbic acid concentrations) are also determined.

中文翻译：

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一锅溶胶-凝胶法研究均匀合成Ag @ SiO 2核-壳纳米结构的机理

摘要

单锅法溶胶-凝胶合成法在室温下合成了单分散的Ag @ SiO ₂核壳结构纳米粒子（NPs），并观察了反应时间的合成过程，以研究其形成机理。在合成核-壳NP的过程中，银（Ag）核NP和二氧化硅（SiO ₂）壳的奥斯特瓦尔德熟化与反应时间平行进行。在反应时间48 h形成均匀稳定的Ag @ SiO ₂核壳NP。原硅酸四乙酯（TEOS）的水解速率在Ag NPs的生长以及Ag @ SiO ₂核壳NPs的最终结构中起着至关重要的作用。单核和多核Ag @ SiO ₂的形成机理讨论了与同步Ag核和SiO ₂壳生长有关的核-壳NP 。还确定了关键参数（水量，TEOS和抗坏血酸浓度）的最佳反应条件。